Polychlorinated biphenyl contamination of feeder cattle
Robens, J.; Anthony, H.D.
Journal of the American Veterinary Medical Association 177(7): 613-615
1980
ISSN/ISBN: 0003-1488 PMID: 6777354 Document Number: 164085
A group of 170 Kansas feedlot steers had access to a backrubber between November 1978 and May 1979. After gaining an average of 1.1 kg/day the 168 survivors were transported to another feedlot where they developed anorexia, dyspnoea, thirst, diarrhoea, abdominal pain and sternal recumbency. PM examination of five of the 51 that died revealed gastrointestinal hyperaemia and intestinal haemorrhages. PCB was demonstrated at 170-1100 ppm in fat, 80 ppm in liver and 44 ppm in kidney. Investigations at the first feedlot revealed up to 69% PCB in the oil used in the backrubber, 95% PCB in samples from the backrubber, up to 1000 ppm PCB in soil from the cattle feedlot, 1.3-17 ppm in fat biopsy samples from pigs allowed access to a backrubber, and 300 ppm in soil from the pig lot. The remaining cattle in the feedlot were destroyed and buried, and soil from the cattle and pig lots was removed and buried. The backrubber oil, which was old transformer fluid, had been purchased eight years previously from a salvage firm. The dead cattle were sent to a rendering plant. Blended grease from this plant was supplied to a broiler and egg producer who found a PCB content of 6-7 ppm. Subsequent batches contained lesser amounts of PCB and were blended accordingly for use in the feed of four poultry operations at 1-3% of the finished feed. Boned meat from the cattle was sold to a dog food manufacturer who voluntarily withdrew the initial batches of dog food from sale. Hides from the cattle were no longer traceable.